1. Field of the Invention
The present invention relates to a socket connector, and more particularly to a low insertion force socket connection in which a cam having a depressing flange is incorporated such that a CPU packet seated thereon can be properly retained in position after the cam is rotated. The present invention also relates to a socket connector in which two cams are incorporated.
2. Description of Related Art
A PGA socket is used for electrically connecting an electronic package to a printed circuit substrate, such as a printed circuit board. The PGA socket, such as U.S. Pat. No. 6,338,640 issued to Lin on Jan. 15, 2002, typically comprises a base supporting a plurality of contacts, a cover including a plurality of insertion holes, and an actuating cam disposed between the base and the cover. The base is mounted on the circuit substrate to form electrical connections between the contacts and circuits on the circuit substrate. The cover is attached to the base prior to assemble to the circuit substrate. When the electronic package is assembled to the cover, the cover is driven by the actuating cam to move horizontally along the base to make the electronic package connects with the contacts. In this typically electrical connector, the actuating cam is only used to drive the cover and does not have other functions.
Another type of PAG socket is designed at present, such as U.S. Pat. No. 7,607,932 issued to Igor on Oct. 14, 2009 discloses a PGA socket. The socket comprises an insulative base with a receiving space for retaining the electronic package and two cams disposed opposite sides of the receiving space of the insulative base. Each cam defines a first position where the electronic package can be easily put in or removed from the receiving space and a second position where the cam is close to a center of the receiving space relative to the first position. When one of the cams is driven to rotate from its first position to its second position, the cam can force the electronic package received in the receiving space to move to a working state. When removing the electronic, said cam back rotates to its first position, then the other cam is driven to rotate from its first position to its second position, the cam force the electronic package to return to its initial position.
Those two cams disclosed and taught in above patent of Igor are only used to rotate to drive the electronic package, while additional arrangement, such as a heat sink and clip are required to retain the CPU in place. However, if the socket is required to have a low profile and/or in some application that a microprocessor package doesn't require a thermal device or equivalent, then the CPU has to be properly retained so as to impose, a restriction of the package motion in the vertical direction.
Therefore, an improved socket is required to overcome the disadvantages of the prior art.